package api

import (
	"encoding/json"
	"net/http"
	"strconv"
	"strings"

	fleetai "crypto-miner-server/internal/ai"
	"crypto-miner-server/internal/db"
)

// FleetAIHandler serves Fleet AI Control API routes.
type FleetAIHandler struct {
	config FleetAIConfigSource
	db     interface {
		ListAIDecisions(agentID string, limit int) ([]db.AIDecisionRecord, error)
	}
}

func NewFleetAIHandler(cfg FleetAIConfigSource, database interface {
	ListAIDecisions(agentID string, limit int) ([]db.AIDecisionRecord, error)
}) *FleetAIHandler {
	return &FleetAIHandler{config: cfg, db: database}
}

func (h *FleetAIHandler) GetConfig(w http.ResponseWriter, r *http.Request) {
	if h.config == nil {
		http.Error(w, "config unavailable", http.StatusServiceUnavailable)
		return
	}
	writeJSON(w, h.config.GetFleetAIConfig())
}

func (h *FleetAIHandler) PutConfig(w http.ResponseWriter, r *http.Request) {
	if h.config == nil {
		http.Error(w, "config unavailable", http.StatusServiceUnavailable)
		return
	}
	var body FleetAIConfigView
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		http.Error(w, "invalid JSON", http.StatusBadRequest)
		return
	}
	if body.AIDecisionIntervalSec < 0 {
		http.Error(w, "ai_decision_interval_sec must be ≥ 0", http.StatusBadRequest)
		return
	}
	if err := h.config.UpdateFleetAIConfig(body); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	writeJSON(w, h.config.GetFleetAIConfig())
}

func (h *FleetAIHandler) GetModels(w http.ResponseWriter, r *http.Request) {
	endpoint := strings.TrimSpace(r.URL.Query().Get("endpoint"))
	if endpoint == "" && h.config != nil {
		endpoint = h.config.GetFleetAIConfig().AIEndpoint
	}
	models, err := fleetai.ListModels(r.Context(), endpoint)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadGateway)
		return
	}
	writeJSON(w, map[string]interface{}{"models": models, "endpoint": endpoint})
}

func (h *FleetAIHandler) GetDecisions(w http.ResponseWriter, r *http.Request) {
	if h.db == nil {
		writeJSON(w, []db.AIDecisionRecord{})
		return
	}
	agentID := strings.TrimSpace(r.URL.Query().Get("agent_id"))
	limit := 50
	if raw := r.URL.Query().Get("limit"); raw != "" {
		if n, err := strconv.Atoi(raw); err == nil && n > 0 {
			limit = n
		}
	}
	rows, err := h.db.ListAIDecisions(agentID, limit)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if rows == nil {
		rows = []db.AIDecisionRecord{}
	}
	writeJSON(w, rows)
}